1. Field of the Invention
This invention relates to formulations containing selected alkyl and/or alkenyl oligoglycosides for cleaning hard surfaces.
2. Description of the Related Art
Cleaning formulations containing alkyl oligoglucosides are already known from a number of prior art publications, cf. European patent applications EP-A 0 199 765, EP-A 0 210 270, EP-A 0 214 285, EP-A 216 301, EP-A 0 282 863 (Henkel), EP-A 0 572 776 (Hxc3xcls), EP-A 0 388 810, EP-A 0 510 870 (Kao) and International patent application WO 92/03582 (RandC). However, these publications only disclose the use of linear alkyl oligoglucosides with an average degree of polymerization of 1.3 to 1.4.
However, it has been found in the past that corresponding formulations are not always satisfactory in regard to their performance properties. Thus, glucoside-containing cleaning formulations show inadequacies in their cleaning effect against obstinate soils. They are occasionally difficult to thicken, i.e. problems are involved in adjusting the viscosity of the products to a value which is low enough to facilitate easy dispensing, but high enough to ensure that the product does not flow too quickly off vertical surfaces. Finally, foaming power, for example in the case of carpet shampoos and oven cleaners, is not always satisfactory. Accordingly, the problem addressed by the present invention was to remedy these deficiencies.
The present invention relates to formulations for cleaning hard surfaces which containxe2x80x94based on the formulationxe2x80x94from 1 to 50, preferably from 1.5 to 15 and more preferably from 2 to 8% by weight of alkyl oligoglucosides corresponding to formula (I):
R1Oxe2x80x94[G]pxe2x80x83xe2x80x83(I)
in which R1 is an at least partly branched alkyl radical containing 9 to 11 carbon atoms, G is a glucose unit and p is a number of 1.4 to 2.0 and preferably a number of 1.5 to 1.7.
It has surprisingly been found that alkyl oligoglucosides based on short-chain oxoalcohols show better cleaning power than glucosides based on linear fatty alcohols of comparable chain length and DP within a selected degree of polymerization (DP) range. The products may readily be adjusted to an in-use viscosity and provides an adequate amount of stable foam, even in the presence of strong alkalis.
Alkyl Oligoglucosides
Alkyl oligoglucosides are known nonionic surfactants which may be obtained by the relevant methods of preparative organic chemistry. EP-A1-0 301 298 and WO 90/03977 are cited as representative of the extensive literature available on the subject. The index p in general formula (I) indicates the degree of oligomerization (DP degree), i.e. the distribution of mono- and oligoglycosides. Whereas p in a given compound must always be an integer, the value p for a certain alkyl oligoglycoside is an analytically determined calculated quantity which is mostly a broken number. The alkyl radical R1 may be derived from primary alcohols containing 9 to 11 carbon atoms. Preferred starting materials are oxoalcohols with a corresponding chain length which may contain 5 to 25 mole-% of branched species from their production. The preferred starting material for the production of the alkyl oligoglucosides is an oxoalcohol marketed by Shell under the name of DOBANOL(copyright) 91.
Surfactants
In addition to the glycosides, the formulations according to the invention may contain other anionic, nonionic, cationic and/or amphoteric and/or zwitterionic surfactants.
Typical examples of anionic surfactants are alkylben-zenesulfonates, alkanesulfonates, olefin sulfonates, alkylether sulfonates, glycerol ether sulfonates, xcex1-methyl ester sulfonates, sulfofatty acids, alkylsulfates, fatty alcohol ether sulfates, glycerol ether sulfates, hydroxy mixed ether sulfates, monoglyceride (ether) sulfates, fatty acid amide (ether) sulfates, mono- and dialkyl sulfosuccinates, mono- and dialkyl sulfosuccinamates, sulfotriglycerides, amide soaps, ether carboxylic acids and salts thereof, fatty acid isethionates, fatty acid sarcosinates, fatty acid taurides, acyl lactylates, acyl tartrates, acyl glutamates, acyl aspartates, alkyl oligoglucoside sulfates, protein fatty acid condensates (particularly wheat-based vegetable products) and alkyl (ether) phosphates. If the anionic surfactants contain polyglycol ether chains, they may have a conventional homolog distribution although they preferably have a narrow-range homolog distribution.
Typical examples of nonionic surfactants are fatty alcohol polyglycol ethers, alkylphenol polyglycol ethers, fatty acid polyglycol esters, fatty acid amide polyglycol ethers, fatty amine polyglycol ethers, alkoxylated triglycerides, mixed ethers and mixed formals, fatty acid N-alkyl glucamides, protein hydrolyzates (particularly wheat-based vegetable products), polyol fatty acid esters, sugar esters, sorbitan esters, polysorbates and amine oxides. If the nonionic surfactants contain polyglycol ether chains, they may have a conventional homolog distribution, although they preferably have a narrow-range homolog distribution.
Typical examples of cationia surfactants are quaternary ammonium compounds and esterquats, more particularly quaternized fatty acid trialkanolamine ester salts. Typical examples of amphoteric or zvitterionic surfactants are alkylbetaines, alkylamidobetaines, aminopropionates, aminoglycinates, imidazolinium betaines and sulfobetaines.
The surfactants mentioned are all known compounds. Information on their structure and production can be found in relevant synoptic works, cf. for example J. Falbe (ed.), xe2x80x9cSurfactants in Consumer Productsxe2x80x9d, springer Verlag, Berlin, 1987, pages 54 to 124 or J. Falbe (ed.), xe2x80x9cKatalysatoren, Tenside und Mineralxc3x6ladditive (Catalysts, Surfactants and Mineral Oil Additives)xe2x80x9d, Thieme Verlag, Stuttgart, 1978, pages 123-217. The percentage content of the other surfactants in the formulations according to the invention may be from 1 to 50% by weight and is preferably from 2 to 25% by weight.
Other Auxiliaries and Additives
The formulations according to the invention may contain other typical auxiliaries and additives such as, for example, liquid builders and sequestering agents such as, for example, citric acid, gluconic acid and alkali metal salts thereof, EDTA and/or NTA, solubilizers such as, for example, butyl glucoside, toluene, xylene and/or cumene sulfonate, lower aliphatic alcohols such as, for example, ethanol, isopropyl alcohol and/or propylene glycol, fatty acids containing 8 to 22 carbon atoms such as, for example, coconut oil or palm kernel oil fatty acid, dicarboxylic acids such as, for example, succinic acid, glutaric acid and/or adipic acid, abrasives such as, for example, silica flour, layer silicates, thickeners, polymers such as, for example, polyethylene glycols having molecular weights in the range from 100,000 to 1,000,000 dalton, alkali bases such as, for example, sodium hydroxide, potassium hydroxide, ammonia solution or triethanolamine for adjusting a basic pH value and perfumes and dyes. The auxiliaries and additives may make up from 1 to 50% by weight and preferably from 2 to 25% by weight of the formulations.
The formulations according to the invention show advantageous foaming and cleaning power. They have an adequate, but not excessively high viscosity, so that they are easy to dispense and flow without difficulty on the surfaces to be cleaned. Typical examples of formulations which fulfil this purpose are multipurpose cleaners, sanitary cleaners, window cleaners, scouring preparations, floor cleaners, carpet shampoos and oven cleaners. The non-aqueous component (corresponding to the active substance content) of the formulations is normally from 5 to 75% by weight. For dilute applications, the active substance content is in the range from 5 to 35 and preferably 7 to 25% by weight and, for concentrates, in the range from 35 to 75 and preferably 50 to 60% by weight.